如何自动映射从Java地图属性POJO类属性

Question

我工作的弹簧引导应用程序和开发弹簧安置（补丁）服务。

我有一个情况，我需要从前端到Java POJO类上PATCH请求中接收一个HashMap中的数据进行映射。

我需要在POJO类映射属性存在于HashMap中的关键。我们需要通过地图迭代，并在地图上的POJO类属性的关键价值相关联。

做这个的最好方式是什么？我知道有一个非常leborious方式，我手动检查地图中的每个键和相应的值在POJO类相应的setter关联。但是，这是如果该POJO类属性的数量众多的数量极其繁琐。

是否有一个有效的方式来实现这一目标？

代码片段

@CrossOrigin
    @RequestMapping(value="/{id}", method = RequestMethod.PATCH)
    public Project editProject(@RequestBody Map<String, String> project, @PathVariable("id") String id) throws Exception {

        logger.info("Inside editProject() API ");

        if(project == null) {
            return null;
        }

        for(String key: project.keySet()) {
            logger.info("Keys passed for update ==> Key(" + key + "): Value(" + project.get(key) + ")");
        }

        Project projectRec = null;

        try {

            logger.info("updateProject() :: Before save :: ");

            projectRec = projectService.updateProjectInfo(project, id);

            logger.info("updateProject() :: After save :: Saved successfully ::: ", projectRec.toString());
        }
        catch (Exception ex) {
            ex.printStackTrace();
            throw ex;
        }

        logger.info("Leaving createProject() API");

        return projectRec;
    }

public Project updateProjectInfo(Map<String, String> projectRec, String id) {

        logger.info("Inside updateProjectInfo() API in ProjectServiceImpl");

        Project dbRec = projectRepository.findOne(id);

        setAttributesfromMaptoDBRec(projectRec, dbRec);

        Project updatedProjectRec = null;

        logger.info(" Leaving updateProjectInfo() API in ProjectServiceImpl");

        return updatedProjectRec;
    }

private void setAttributesfromMaptoDBRec(Map<String, String> updatedProjectRecMap, Project updatedProjectRec) {

        logger.info(" Inside setAttributesfromMaptoDBRec() API in ProjectServiceImpl");

        Set<String> nonUpdateableAttributes = ProjectServiceImpl.nonUpdateableKeys.get(ProjectServiceImpl.nonUpdateable);

        if(updatedProjectRecMap == null) {
            logger.warn(" Input Map to service is null in ProjectServiceImpl ===> " + (updatedProjectRecMap == null));
            return;
        }

        for(String key: updatedProjectRecMap.keySet()) {

            logger.info(" Project property ===>  " + key);

            logger.info(" nonUpdateableAttributes contains key  ===> " + nonUpdateableAttributes.contains(key));

            if(!nonUpdateableAttributes.contains(key)) {
                try {
                    System.out.println("Field name: " + updatedProjectRec.getClass().getField(key));
                    System.out.println("HOW TO AUTOMATICALLY SET THE ATTRIBUTE TO THE POJO CLASS BASED ON THE KEY ??");
                } catch(Exception ex) {
                    ex.printStackTrace();
                }

            }
        }


    }

Answer 1

我已经做了类似的事情早就回了杰克逊使用API​​数据绑定。不知道，但是这可能会有所帮助：

import java.util.Map;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.ObjectMapper;

public class ObjectMarshalUtility {

    public static <T> Map marshalObject(T obj){
        ObjectMapper oMapper = new ObjectMapper();
        oMapper.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);
        return oMapper.convertValue(obj, Map.class);
    }

    public static <T> T unMarshalObject(Class<T> classType, Map<String, Object> map){
        ObjectMapper oMapper = new ObjectMapper();
        oMapper.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);
        return oMapper.convertValue(map, classType);
    }
}

用于将DTO到地图：

Map<String,Object> searchInputMap=ObjectMarshalUtility.marshalObject(searchInputDTO);

用于将映射到DTO：

SearchInputDTO searchInputDTO=ObjectMarshalUtility.unMarshalObject(searchInputMap);